Liquid crystal device and liquid crystal apparatus

• US 5,841,497 A
• Filed: 07/23/1996
• Issued: 11/24/1998
• Est. Priority Date: 07/28/1995
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Terada, Masahiro, Sato, Koichi, Shinjo, Kenji, Yamada, Syuji
• Primary Examiner(s): McPherson, John A.
• Application Number:
  US08/681,350
• Time in Patent Office: 854 Days
• Field of Search: 349/128, 349/184, 252/299.01, 252/299.61, 252/299.62, 252/299.63, 252/299.64, 252/299.65, 252/299.66, 252/299.67, 252/299.68
• US Class Current: 349/128
• CPC Class Codes: C09K 19/34 containing at least one heterocyclic ring
• CPC Class Codes: C09K 19/3458 Uncondensed pyrimidines
• CPC Class Codes: G02F 1/133723 Polyimide, polyamide-imide

Abstract

A liquid crystal device is constituted by a pair of substrates each having thereon an electrode for voltage application, a chiral smectic liquid crystal composition disposed between the substrates so as to assume at least two optically stable states. At least one of the substrates is provided with an alignment control layer having a thickness of at most 200 Å or comprising polyimide. The substrates have been subjected to different aligning treatments at their opposite faces each contacting the composition. The composition comprises at least three fluorine-containing mesomorphic compounds each comprising a fluorocarbon terminal portion and a hydrocarbon terminal portion, the terminal portions being connected with a central core, the compounds having smectic mesophase or latent smectic mesophase; said at least three mesomorphic compounds comprising a compound having a fluorocarbon terminal portion containing one catenary ether oxygen atom, a compound having a fluorocarbon terminal portion containing two catenary ether oxygen atoms, and a compound having a fluorocarbon terminal portion containing three catenary ether oxygen atoms. The above liquid crystal device is effective in improving a duration margin to provide good drive characteristic when driven.

Claims

1. A liquid crystal device, comprising:

a pair of substrates each having thereon an electrode for voltage application, a chiral smectic liquid crystal composition disposed between the substrates,

wherein at least one of the substrates is provided with an alignment control layer having a thickness of at most 200 Å and

having been subjected to rubbing, the substrates having been subjected to different aligning treatments at their opposite faces each contacting the chiral smectic liquid crystal composition , and

the chiral smectic liquid crystal composition comprises at least three fluorine-containing mesomorphic compounds each comprising a fluorocarbon terminal portion having at least one catenary ether oxygen atom and a hydrocarbon terminal portion, the terminal portions being connected with a central core, the compounds having smectic mesophase or latent smectic mesophase;

said at least three mesomorphic compounds comprising at least one species of a compound having a fluorocarbon terminal portion containing one catenary ether oxygen atom, at least one species of a compound having a fluorocarbon terminal portion containing two catenary ether oxygen atoms, and at least one species of a compound having a fluorocarbon terminal portion containing three catenary ether oxygen atoms.

2. A device according to claim 1, wherein one of the substrates is provided with an alignment control layer having been subjected to rubbing.

3. A liquid crystal device according to claim 1, wherein said fluorocarbon terminal portion of each of said at least three fluorine-containing mesomorphic compounds is represented by the formula --D² --(C_xb F_2xb --O)_za --C_ya F_2ya+1, where xb is independently 1-10 independently for each (C_xb F_2xb --O);

ya is 1-10;

za is 1-10;

--D² -- is --CO--O--C_rc H_2rc, --O--C_rc H_2rc --, --C_rc H_2rc --, --O--(C_sa H_2sa --O)_ta --C_rd H_2rd --, --O--SO₂ --, --SO₂ --, --SO₂ --C_rc H_2rc --, --C_rc H_2rc --N(C_pb H_2pb+1)--SO₂ --, --C_rc H_2rc --N(C_pb H_2pb+1)--CO--, or a covalent bond where rc and rd are independently 1-20;

sa is independently 1-10 for each (C_sa H_2sa --O);

ta is 1-6; and

pb is 0-4.

4. A liquid crystal device according to claim 1, wherein each of said at least three fluorine-containing mesomorphic compounds is represented by the general formula (II):

Formula (II);

##STR27## where A⁴, A⁵ and A⁶ are each independently denote ##STR28## gb, hb and ib are each independently an integer of 0-3 with the proviso that the sum of gb+hb+ib be at least 2;

each L³ and L⁴ are independently a single bond, --CO--O--, --O--CO--, --CO--S--, --S--CO--, --CO--Se--, --Se--CO--, --CO--Te--, --Te--CO--, --(CH₂ CH₂)_ka -- where ka is 1-4, --CH═

CH--, --C═

C--, --CH═

N--, --N═

CH--, --CH₂ --O--, --O--CH₂ --, --CO--or --O--;

X², Y² and Z² are each a substituent of A⁴, A⁵ and A⁶, respectively, and each X₂, Y₂ and Z₂ are independently --H, --Cl, --F, --Br, --I, --OH, --OCH₃, --CH₃, --CF₃, --O--CF₃, --CN or --NO₂ ;

each jb, mb and nb are independently an integer of 0-4;

J² is --CO--O--C_rc H_2rc --, --O--C_rc H_2rc --, --C_rc H_2rc --, --O--(C_sa H_2sa --O)_ta --C_rd H_2rd --, --O--SO₂ --, --SO₂ --, --SO₂ --C_rc H_2rc --, --C_rc H_2rc --N(C_pb H_2pb+1)--SO₂ -- or --C_rc H_2rc --N(C_pb H_2pb+1)--CO-- where rc and rd are independently 1-20;

sa is independently 1-10 for each (C_sa H_2sa --O), ta is 1-6;

pb is 0-4;

R⁴ is --O--(C_qc H_2qc --O)_wa --C_qd H_2qd+1, --(C_qc H_2qc--O)_wa --C_qd H_2qd+1, --C_qc H_2qc --R⁶, --O--C_qc H_2qc --R⁶, --CO--O--C_qc H_2qc --R⁶, or O--CO--C_qc H_2qc --R⁶ which may be either straight chain or branched where R⁶ is --O--CO--C_qd H_2qd+1 ;

--CO--O--C_qd H_2qd+1, --Cl, --F, --CF₃, --NO₂, --CN or --H;

qc and qd are independently 1-20;

wa is 1-10;

R⁵ is (C_xb F_2xb --O)_za --C_ya F_2ya+1, where xb is independently 1-10 for each (C_xb F_2xb --O);

ya is 1-10; and

za is 1-10.

5. A device according to claim 4, wherein each of said at least three fluorine-containing mesomorphic compounds represented by the formula (II) has a central core containing benzene ring and pyrimidine ring.

6. A device according to claim 1, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds each in an amount of at least 10 wt. %.

7. A device according to claim 1, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds in a total amount of at least 30 wt. %.

8. A device according to claim 1, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds in a total amount of at least 50 wt. %.

21. A liquid crystal apparatus, including a liquid crystal device according to claim 1 or 9.

9. A liquid crystal device, comprising:

a pair of substrates each having thereon an electrode for voltage application, a chiral smectic liquid crystal composition disposed between the substrates,

wherein at least one of the substrates is provided with an alignment control layer comprising polyimide and the substrates have been subjected to different aligning treatments at their opposite faces each contacting the chiral smectic liquid crystal composition, and

the chiral smectic liquid crystal composition comprises at least three fluorine-containing mesomorphic compounds each comprising a fluorocarbon terminal portion having at least one catenary ether oxygen atom and a hydrocarbon terminal portion, the terminal portions being connected with a central core, the compounds having smectic mesophase or latent smectic mesophase;

said at least three mesomorphic compounds comprising at least one species of a compound having a fluorocarbon terminal portion containing one catenary ether oxygen atom, at least one species of a compound having a fluorocarbon terminal portion containing two catenary ether oxygen atoms, and at least one species of a compound having a fluorocarbon terminal portion containing three catenary ether oxygen atoms.

10. A device according to claim 9, wherein said polyimide has a recurring unit represented by the following formula (III):

##STR29## in which K is ##STR30## L¹¹ and L¹² independently denote ##STR31## or an alkylene group having 1-20 carbon atoms;

M¹¹ is a single bond or --O--; and

a is 0, 1 or 2.

11. A device according to claim 9, wherein one of the substrates is provided with an alignment control layer having been subjected to rubbing.

12. A device according to claim 9, wherein the alignment control layer comprising polyimide is provided to at least one of the substrates and has been subjected to rubbing.

13. A device according to claim 9, wherein the alignment control layer comprising polyimide is provided to at least one of the substrates and has a thickness of at most 200 |.

14. A liquid crystal device according to claim 9, wherein said fluorocarbon terminal portion of each of said at least three fluorine-containing mesomorphic compounds is represented by the formula --D² --(C_xb F_2xb --O)_za --C_ya F_2ya+1, where xb is independently 1-10 independently for each (C_xb F_2xb --O);

ya is 1-10;

za is 1-10;

--D² -- is --CO--O--C_rc H_2rc, --O--C_rc H_2rc --, --C_rc H_2rc --, --O--(C_sa H_2sa --O)_ta --C_rd H_2rd --, --O--SO₂ --, --SO₂ --, --SO₂ --C_rc H_2rc --, --C_rc H_2rc --N(C_pb H_2pb+1)--SO₂ --, --C_rc H_2rc --N(C_pb H_2pb+1)--CO--, or a covalent bond where rc and rd are independently 1-20;

sa is independently 1-10 for each (C_sa H_2sa --O);

ta is 1-6; and

pb is 0-4.

15. A liquid crystal device according to claim 9, wherein each of said at least three fluorine-containing mesomorphic compounds is represented by the general formula (II):

Formula (II);

##STR32## where A⁴, A⁵ and A⁶ are each independently denote ##STR33## gb, hb and ib are each independently an integer of 0-3 with the proviso that the sum of gb+hb+ib be at least 2;

each L³ and L⁴ are independently a single bond, --CO--O--, --O--CO--, --CO--S--, --S--CO--, --CO--Se--, --Se--CO--, --CO--Te--, --Te--CO--, --(CH₂ CH₂)_ka -- where ka is 1-4, --CH═

CH--, --C═

C--, --CH═

N--, --N═

CH--, --CH₂ --O--, --O--CH₂ --, --CO--or --O--;

X², Y² and Z² are each a substituent of A⁴, A⁵ and A⁶, respectively, and each X₂, Y₂ and Z₂ are independently --H, --Cl, --F, --Br, --I, --OH, --OCH₃, --CH₃, --CF₃, --O--CF₃, --CN or --NO₂ ;

each jb, mb and nb are independently an integer of 0-4;

J² is --CO--O--C_rc H_2rc --, --O--C_rc H_2rc --, --C_rc H_2rc --, --O--(C_sa H_2sa --O)_ta --C_rd H_2rd --, --O--SO₂ --, --SO₂ --, --SO₂ --C_rc H_2rc --, --C_rc H_2rc --N(C_pb H_2pb+1)--SO₂ -- or --C_rc H_2rc --N(C_pb H_2pb+1)--CO-- where rc and rd are independently 1-20;

sa is independently 1-10 for each (C_sa H_2sa --O), ta is 1-6;

pb is 0-4;

R⁴ is --O--(C_qc H_2qc --O)_wa --C_qd H_2qd+1 --(C_qc H_2qc --O)_wa --C_qd H_2qd+1, --C_qc H_2qc --R⁶, --O--C_qc H_2qc --R⁶, --CO--O--C_qc H_2qc --R⁶, or O--CO--C_qc H_2qc --R⁶ which may be either straight chain or branched where R⁶ is --O--CO--C_qd H_2qd+1 ;

--CO--O--C_qd H_2qd+1, --Cl, --F, --CF₃, --NO₂, --CN or --H;

qc and qd are independently 1-20;

wa is 1-10;

R⁵ is (C_xb F_2xb --O)_za --C_ya F_2ya+1, where xb is independently 1-10 for each (C_xb F_2xb --O);

ya is 1-10; and

za is 1-10.

16. A device according to claim 15, wherein each of said at least three fluorine-containing mesomorphic compounds represented by the formula (II) has a central core containing benzene ring and pyrimidine ring.

17. A device according to claim 9, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds each in an amount of at least 10 wt. %.

18. A device according to claim 9, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds in a total amount of at least 30 wt. %.

19. A device according to claim 9, wherein the liquid crystal composition comprises said at least three fluorine-containing mesomorphic compounds in a total amount of at least 50 wt. %.

20. A device according to claim 9, wherein the substrates include a substrate provided with an alignment control layer comprising polyimide and having been subjected to rubbing, and a substrate provided with an alignment control layer comprising a silane coupling agent.